2354Micro-surfacing

2354.1DESCRIPTION

Micro-surfacing is a mixture of polymer modified asphalt emulsion, well-graded crushed mineral Aggregate, mineral filler, water, and other additives.

2354.2MATERIALS

A Bituminous Material A.1 Micro-surfacing Emulsified Asphalt: Polymer modified CQS-1hP for rut filling or CQS-1P for non-rut filling applications ........................................................................... 3151.2H A.2 Bituminous Emulsion for Fog Seal ................................................................ 3151.2D.1.b B Aggregate ........................................................................................................................ 3139.2D C Mineral Filler E Mixture Requirements E.1 Mix Design Fourteen Business Days before beginning production, submit to the Engineer a complete mix design and a 150 pound Aggregate sample. List the source of Materials used for the mix design. Show that the individual proportions of each of the Materials , when combined, meet the mix design requirements of Table 2354.2-1. Testing procedures may be obtained from the International Slurry Surfacing Association (ISSA). Table 2354.2-1 Mix Design Test Requirements Test Description Specification For CQS-1hP Specification For CQS-1P ISSA TB-114 Wet stripping ≥ 90 ≥ 90 ISSA TB-100* Wet track abrasion loss, 1 hour soak ≤ 1.8 ounce/square feet Using a bath soak/run Temperature of 77ºF ≤ 1.8 ounce/square feet Using a bath soak/run Temperature of 66ºF ISSA TB-100* Wet track abrasion loss, 6 Calendar Day soak ≤ 2.6 ounce/square feet Using a bath soak/run Temperature of 77ºF ≤ 2.6 ounce/square feet Using a bath soak/run Temperature of 66ºF ISSA TB-144 Saturated abrasion compatibility ≤ 3 g loss ISSA TB-113 Mix time at 77°F Controllable to ≥120 s ISSA TB-113 Mix time at 100°F Controllable to ≥35 s * For ISSA Type II and Type III aggregates, modify ISSA TB-100 to use the full aggregate gradation and a 3/8 inch thick mold when preparing samples for testing. Test temperature range is +/- 5 ºF

Provide a Job Mix Formula (JMF) containing from 7.0 percent to 10.5 percent of residual asphalt by dry weight of Aggregate and 0.25 percent to 3.0 percent mineral filler by dry weight of Aggregate. Submit a new mix design to the Engineer, if the Aggregate source, Aggregate blend, or asphalt emulsion source change.

E.2 Mix Design Format Submit the final mix design that includes the following information:

2354.3CONSTRUCTION REQUIREMENTS

A Equipment A.1 Mixing Machine Provide a continuous micro-surfacing lay down machine. Provide a positive connection conveyer belt Aggregate delivery system and an inter-connected positive displacement, water-jacketed gear pump to accurately proportion Aggregate and asphalt emulsion. Locate the mineral filler feed to ensure that the proper amount of mineral filler drops on the A ggregate before discharging into the pugmill. Provide a pugmill meeting the following characteristics:

recommendations Introduce the asphalt emulsion within the first third of the mixer length to ensure proper mixing of Materials before exiting from the pugmill. Use a self-propelled front feed and continuous loading machine with dual driving stations. Provide a remote forward speed control at the back mixing platform for the back operator to control forward speed and the level of mixture in the spreader box . Use sufficient transport units to assure a continuous operation during mix production and application. Provide individual volume or weight controls for proportioning each Material . Position the controls for access at any time. Use the controls to calibrate the operation before production and to determine the amount of each Material used at any time.

Provide a water pressure system and nozzle type spray bar to spray water ahead of and outside the spreader box, if necessary. Dampen the surface. Do not create free flowing water ahead of the spreader box. A.2 Spreader Box Spread the mix uniformly, using a mechanical type spreader box, attached to the mixer and equipped with spiral augers mounted on adjustable shafts . Continually agitate and distribute the mixture to prevent stagnation, excessive Material build-up, or lumps. Equip the spreader box with front and rear flexible seals to achieve direct contact with the surface of the R oad. Use a secondary strike off attached to the spreader box to provide a smooth finished surface texture . Do not use burlap drags. A.3 Rut Filling Box Provide a rut filling box meeting the following characteristics:

A.4 Weighing Equipment Use portable Scales to weigh Material certified in accordance with 1901.6, “Mass,” and as modified as follows:

more frequent B Operations B.1 Micro-surfacing Types B.1.a Rut Fill Type 3, per 3139.2D, “Micro-surfacing” Rut fill pavement segments longer than 1,000 feet, if the average rut depth is greater than 1/2 inch. Provide a rut box for each designated wheel track. Provide a clean overlap and straight edges between wheel tracks. Construct each rutted wheel track with a crown 1/4 inch per inch of rut depth to allow for proper consolidation by traffic. B.1.b Scratch Course Type 2 or Type 3 per 3139.2D, “Micro-surfacing,” as shown on the Plans Use a metal strike off bar on the spreader box. Do not allow excess buildup or uncovered areas. B.1.c Surface Course Type 2, per 3139.2D, “Micro-surfacing” Apply full lane width in one course. Do not allow excess buildup or uncovered areas. B.2 Pre-Paving Meeting Hold a pre-paving meeting with the Engineer on-site before beginning Work to discuss the following:

B.3 Calibration Calibrate each mixing machine before use. Maintain documentation showing individual calibrations of each Material at various settings relating to the machine’s metering devices. Supply Materials and Equipment, including Scales and containers for calibration (MA 1 ISSA Inspector’s Manual). Recalibrate machines on the job after a change in Aggregate, asphalt emulsion source, or repairs are made to the Aggregate feeding belt, gate, or emulsion pump. B.4 Test Strip Construct a test strip in a location approved by the Engineer. For each machine used, construct a one-lane wide test strip 1,000 feet long. Begin construction after dark, at least 1 hour after sunset and at least 1 hour before sunrise. Check for variances in surface texture and appearance. Do not construct the test strip until the emulsion temperature falls below 122 °F. Allow traffic on the test strip within 1 hour after application; the Engineer will evaluate whether any damage occurs. The Engineer will inspect the completed test strip again after 12 hours of traffic to determine if it is acceptable. The Contractor may begin full production after the Engineer accepts a test strip. The Engineer may waive the test strip requirement, if the Contractor submits evidence of the successful construction of a test strip on another project constructed during the same construction season, using the same mix design. B.5 Surface Preparation Clean the surface immediately before placing the micro-surfacing. B.6 Fog Seal Apply fog seal to concrete surfaces and bituminous surfaces if required by the Engineer before the first course of micro-surfacing. Provide and apply CSS-1h emulsion in accordance with 2355, “Bituminous Fog Seal,” and the following:

0.10 gallons per square yard. Limit the daily application of fog seal to the pavement area receiving micro-surfacing that day. Do not open fog sealed areas to traffic until after applying and curing the first course of micro-surfacing. Allow the fog seal to cure before applying micro-surfacing.

application of the fog seal and during micro-surfacing. B.7 Surface Quality Construct the surface course without excessive scratch marks, tears, rippling, and other surface irregularities. Repair tear marks wider than 1/2 inch and longer than 4 inches. Repair transverse ripples or streaks deeper than 1/4 inch if measured by a 10 foot straightedge. Construct longitudinal joints with no greater than 1/4 inch overlap thickness if measured with a 10 foot straightedge, and less than 3 inch overlap on adjacent passes. Locate longitudinal construction joints and lane edges to coincide with the proposed painted lane lines shown on the Plans. Place overlapping passes on the uphill side to prevent water from ponding.

Construct transverse joints with no greater than 1/8 inch difference in elevation across the joint if measured with a 10 foot straightedge. Construct edgelines along curbs and Shoulders, with no greater than 2 inches of width variance in any 100 foot length. Do not allow runoff in these areas. Stop micro-surfacing work, if requirements of this section are not being met. Make corrections as approved by the Engineer before restarting Work. Protect drainage Structures, monument boxes, water shut-offs, and any other utility Structures within the Project or staging areas. Make repairs to micro-surfacing defects to the full width of paving pass with spreader box. Do not perform hand repairs after micro-surfacing mix has set. B.8 Open to Traffic Do not open the micro-surface to traffic until the micro-surface cures sufficiently to prevent pickup by vehicle tires. The Department considers properly constructed micro-surface as micro-surface capable of carrying normal traffic within 1-hour of application without damage. Protect the new surface from potential damage at Intersections and driveways. Repair damage to the surface caused by traffic at no additional cost to the Department. Confirm that the micro surface cured within 1-hour on the first day of production. If the micro-surface has not cured within 1 hour, stop Work and construct a new test strip. The Department will consider any spot check or test strip failure as unacceptable Work in accordance with 1512, “Unacceptable and Unauthorized Work.” B.9 Weather and Time Limitations Begin construction when the air and pavement surface temperatures are at least 50 °F and rising. Do not place micro-surfacing during rain, or if the forecast indicates a temperature below 32°F within 48 hours of the planned micro-surfacing. Do not start Work after September 15. C Contractor Sampling, Testing, and Documentation Perform Quality Control (QC) sampling and testing. C.1 Emulsion Provide a Material Bill of Lading (BOL) for each batch of emulsion used. Include the supplier’s name, plant location, emulsion grade, residual asphalt content, volume (gross and net, gallons), and batch number. C.2 Aggregate Sample and test according to the Schedule of Materials Control. Provide daily QC test results to the Engineer. C.2.a Gradation and JMF Tolerance The tolerances for the JMF are listed in Table 3139.2-10. The tolerance may not exceed the gradation limits. C.2.b Moisture Content Perform additional testing upon a visible change in moisture. Use the average daily moisture to calculate the oven dry weight of the Aggregate.

C.3 Asphalt Binder Application Rate Randomly calculate and record the percent asphalt content of the mixture from the Equipment counter readings. The asphalt tolerance is ±0.5 percent residual asphalt. C.4 Design Application Rate The design application rate shall be the total amount of micro-surfacing Material placed to meet the requirements for cross-section and surfacing. This amount will be the combination of all courses placed. C.5 Documentation Provide a daily report containing the following information to the Engineer within one Working Day:

2354.4METHOD OF MEASUREMENT

The Engineer will measure the Bituminous Material for Micro-Surfacing and undiluted Bituminous Material for Fog Seal by volume at 60°F. The Engineer will measure the Micro Surfacing Rut Fill, Micro Surfacing Scratch Course, and Micro Surfacing Surface Course by daily average weight of oven dry weight of Aggregate .

2354.5BASIS OF PAYMENT

The Contract gallon price for the accepted quantity of Bituminous Material for Micro -surfacing includes the costs of additives as indicated above, constructing the micro-surfacing as shown in the Plans, and all testing. The Department will pay for bituminous Material for fog seal in accordance with 2355.5, ”Bituminous Fog Seal, Basis of Payment.” A Monetary Adjustment The Department must apply Incentives and Disincentives and may apply monetary deductions for Micro-surfacing. The amounts of these adjustments are deemed reasonable. The Department may deduct $5,000 from the Contract amount for each spot check failure and anytime there is evidence of the system being out of specification per 2354.2E.1, “Mix Design,” as determined by tests in 2354.3C, “Contractor Sampling, Testing, and Documentation.” The Engineer will calculate monetary deductions for failing gradations based on 2 percent of the Unit Price per ton for each 1 percent passing result outside of a gradation range for all S ieves (Table 3139.2-10). The monetary deduction will apply to the quantity of Material represented by the failing

test(s). The Department may apply this monetary deduction schedule for micro-surfacing construction to non-warranty Work. B Schedule The Department will pay for micro-surfacing on the basis of the following schedule: Item No. Item Unit

2354.506 Bituminous Material for Micro-surfacing gallon

9 Micro-surfacing Rut Fill ton

9 Micro-surfacing Scratch Course ton

9 Micro-surfacing Surface Course ton